zabbix_login

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden of behavioral disclosure. It states that a session is established and that tokens are cached, but it does not disclose side effects (e.g., idempotency, what happens if already authenticated), prerequisites (e.g., credentials, API endpoint), or return behavior. This is insufficient for a tool with no annotation safety information.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two sentences long, with no filler. The first sentence states the core purpose, and the second provides relevant context about caching. Every word earns its place, making it highly concise and well-structured.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Despite having no params and no output schema, the description is incomplete for an agent to know whether to call this tool explicitly. The second sentence hints at automatic relogin but does not clarify if manual invocation is ever needed, nor does it mention any prerequisites. This ambiguity makes the description insufficient for confident tool selection.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The input schema has zero parameters, so the baseline is 4. The description does not need to explain parameters, and it adds no parameter-related information. Since there are no parameters to clarify, a score of 4 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool 'Establishes an authenticated session with the Zabbix API', using a specific verb and resource. However, it does not explicitly contrast with the sibling zabbix_logout, and the addition about 'token caching and re-login on demand' slightly muddies whether the tool is meant for manual use or automatic handling.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no explicit guidance on when to use this tool vs. alternatives. The note that the client 'handles token caching and re-login on demand' implies that manual login may not always be necessary, but it does not clearly state when the agent should invoke this tool or rely on automatic behavior.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.